This invention generally relates to golf clubs and more particularly to a golf club having vibration dampening features.
Golf clubs typically have a grip on one end of a long, narrow shaft and a club head on the other end of the shaft. When the club head strikes a golf ball, kinetic energy transfers from the golf club to the golf ball. The energy transfer propels the golf ball away from the golfer in a direction roughly parallel to the path of the club head at impact.
Golf clubs have a sweet spot on the club head surface. Striking the golf ball with the sweet spot of the club head typically feels best to the golfer and produces the best energy transfer from the golf club to the golf ball. Moreover, striking the golf ball with the sweet spot transfers only small vibrations to the club. Most golfers do not possess the skill required to hit a golf ball with the sweet spot during every swing. Striking the ball outside the sweet spot or missing the ball and striking the ground or a foreign object, causes a noticeable increase in the vibrational response of the golf club. Added vibration can be annoying and uncomfortable for the golfer. Moreover, reducing the vibration may reduce the likelihood of injury to the golfer, for example as from tendinitis. Golf club designers typically measure these vibrations when designing new golf clubs to better understand the response characteristics of the club. These vibrational frequency measurement techniques are well known by those skilled in the art, as exemplified by U.S. Pat. Nos. 5,616,832 (Nauck) and 5,703,294 (McConnell et al.).
Golf club designers have attempted to dampen these unwanted vibrations in golf clubs. For example, one design incorporates a collapsible shaft that retracts a short distance into the grip when the club strikes an immovable object, such as the ground. Shaft movement into the grip allegedly reduces the induced vibration. Another design incorporates vibration absorbing materials, such as elastomers, inside the grip or shaft or as a club head coating. These elastomeric materials allegedly dampen unwanted vibrations. A third design incorporates an elastomeric vibration damping device mounted on the grip of the golf club. This design extends outward from the shaft, rather than inward, and is not compatible with an existing golf club grip. Moreover, the reduced density of the elastomeric material limits its ability to dampen vibrations.
Each of these devices is designed to be incorporated into a new golf club, rather than as an addition to a conventional club. Accordingly, there is a need for a vibration damper adapted for use with existing golf clubs. Such a vibration damper would be useful, because adding a low-cost vibration dampening device to existing golf clubs would be beneficial.
Moreover, current designs do not account for differences in vibrational response, which depend on the club geometry. Thus, there is a need for a vibration damper that reduces vibrational response in different golf clubs.
Among the several objects and features of the present invention may be noted the provision of a vibration damper which attaches to an existing golf club for reducing the vibration felt by the golfer; the provision of such a vibration damper which does not negatively affect golf club feel; and the provision of such a vibration damper which installs without tools and retains itself within the golf club without fasteners.
Briefly, apparatus of this invention is a vibration damper for a golf club. The golf club includes a shaft having a grip at a first end for gripping the club and a head at a second end opposite the first end for striking a golf ball. The grip is constructed of an elastomeric material and includes a tubular shell with a hollow interior sized for receiving the first end of the shaft. A cap at one end of the grip has an opening therethrough extending into the hollow interior of the shell. The vibration damper comprises an elongate element sized and shaped for insertion through the opening of the grip so a first end of the element is disposed inside the hollow interior of the grip and a second end of the element, opposite the first end, is positioned adjacent the cap. A tuned mass is mounted on the first end of the element such that the mass is freely suspended within the hollow interior of the grip when the elongate element is inserted through the opening of the grip. When the golf club strikes a golf ball, the resulting vibration of the club is transferred to the elongate element and the tuned mass such that the vibration of the damper reduces the vibration of the club, decreasing uncomfortable vibrations felt by the golfer. Tuning the tuned mass and vibration damper for a specific golf club is discussed infra.
In another aspect, apparatus of the present invention includes a golf club comprising a vibration damper generally as set forth above.
In yet another aspect, apparatus of the present invention includes a golf club grip comprising a vibration damper generally as set forth above.
Other objects and features will be in part apparent and in part pointed out hereinafter.